There are a variety of applications in which it may be desirable to determine the location of objects in an image. For example, in an optical character recognition (OCR) application used to recognize text characters in an image of a document, it may be desirable to determine the bounds and/or position of the document on the image. Thus, in the OCR application, it may be desirable to distinguish the document portion of the image from the rest of the image. This allows the OCR application to focus only on the document portion of the image.
Another application in which it may be desirable to determine the location of objects in an image relates to the automated processing (e.g., sorting, routing, postage checking, etc.) of parcels of mail. In this application, an image of a mail parcel is generated and analyzed in order to determine information, such as the destination address, return address, and indicia (i.e., postage mark, stamp, etc.) on the parcel. This information can then be used to determine how to process the mail parcel.
It will be appreciated that mail parcels may have a variety of shapes and sizes. The area scanned in order to generate the image of the parcel must thus be large enough to accommodate these varying shapes and sizes. As a result, the parcel may comprise only a portion of the image. The orientation of the parcel in the image may also vary. Thus, it is desirable to distinguish the portion of the image including the parcel from other areas in the image.